| 摘要: | 還原碴與爐碴細粒料皆為電弧爐煉鋼之副產品，還原碴經適當處理後能表現出類似水泥的膠結效果，而爐碴細粒料經過前置處理後則在某些情況下能取代部分天然粒料使用。如能將兩者結合製作成取代水泥混凝土的環保混凝土材料，不僅可處理這些工業副產品，同時更可減少水泥混凝土的使用，進一步達到多重效益。 本研究主要以鹼活化技術活化還原碴，並加入爐石取代部分還原碴以降低活化劑用量，再以此膠結材料結合爐碴細粒料進行抗壓強度、體積穩定性與耐久性等相關詴驗。最後設計製作28天抗壓強度為210 kgf/cm2 之鹼活化還原碴混凝土，並進行可行性評估。 研究顯示爐石取代量50％，鹼活化劑之含鹼當量4％，鹼模數比0.75的配比配合爐碴細粒料取代，抗壓強度可達規範標準，耐久性方面則優於使用水泥漿體的詴體，但仍有乾燥收縮量遠大於水泥的問題。混凝土方面，使用天然粒料的混凝土強度可達28天的目標強度，而使用爐碴細粒料完全取代的混凝土雖未達目標強度，但已相當接近目標，評估所有實驗結果，爐碴細粒料應用於製作鹼活化還原碴混凝土是可行的。 The reductive slag and slag fine aggregates are the by-products of EAF steel-making. After an appropriate process, reductive slag can show a similar cementation effect as the cement, and slag fine aggregates can be used in certain cases to replace part of the natural aggregates after the pre-processing is made. If we can combine both products to make environmentally friendly concrete material which replaces the cement concrete, we not only deal can with these industrial by-products, but also reduce the use of cement concrete, further to achieve multiple benefits. This study aims at activating reductive slag by using alkali-activated technology, adding furnace slag to replace part of reductive slag to reduce the dosage of activating agent, and then conducting experiments related to concrete compressive strength, volume stability and durability using the combination of this cementing material and slag fine aggregates. Finally, we design a production of the alkali-activated reductive slag concrete with 28-day compressive strength of 210 kgf / cm 2, and conduct the feasibility studies. Study shows that with the furnace slag replacement rate of 50%, alkaline activator 4%(by Na2O), alkali modulus 0.75, replacing natural aggregates with slag fine aggregates, the compressive strength of the mortar can reach normative standards, and its durability is superior to those of cement paste samples. However, its drying shrinkage is much greater than those of cement. As for concrete, the compressive strength of concrete using natural aggregates can reach the 28-day targeted strength, while the compressive strength of concrete with natural aggregates completely replaced with slag fine aggregates doesn’t reach the target, yet is very close to it. Assessing all the experimental results of this study, it is feasible to use slag fine aggregates in the production of alkali-activated reductive slag concrete. |
